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In comparative study your objects are specimens or cases which are similar in some respects (otherwise, it would not be meaningful to compare them) but they differ in some respects. These differences become the focus of examination. The goal is to find out why the cases are different: to reveal the general underlying structure which
allows and generates such a variation.
The design of comparative research is very simple. You do not even need any earlier model or theory to start with (though it will help if there is one). Therefore it suits well to exploratory studies where scientists try to move from the initial level of case studies to a more advanced level of general theoretical invariances, like causality or evolution. Comparation is one of the few methods that you can use for explicating or utilizing tacit knowledge or tacit attitudes. You show e.g. in parallel two slides of two slightly different objects and ask people to explain verbally their differences.
The method is also versatile: you can use it in detail work as a complement to other methods, or the entire structure of a research project can consist of the comparison of just two cases.
| Observed state of things | ||
|---|---|---|
| Case 1 | Case 2 | |
| Aspect A | A1 | A2 |
| Aspect B | B1 | B2 |
| Aspect C | C1 | C2 |
The final goal of research is usually to reveal the systematic structure, invariance, that is true not only for the cases that were studied, but for the entire group (population) where the cases came from, or perhaps even for all the comparable cases in the universe. In other words, the goal is to generalize the findings.
The comparative method is often used in the early stages of the development of a branch of science. It can help the researcher to ascend from the initial level of exploratory case studies to the more advanced level of general theoretical models.
Of course, it would be foolhardy to assert anything about a larger group, let alone the universe, if your study consisted of just two cases. The plausibility of your generalisation will increase, if you have instead of "Case 1", several cases from the same group, let us call it "Group 1", and similarly several cases from "Group 2". If all or the majority of these pairs show the same invariance, its credibility will quickly rise. There are statistical methods to calculate the credibility, or statistical significance of the findings.
Sometimes the groups from which you want information are so small that you can study all their members (i.e. you make a total study). The other alternative is that you pick samples from the groups and then generalize the results.
In the case that you need to compare more than two groups, or the number of cases is large, the study begins to approach classification, a method that is discussed on another page.
In comparative like in most other studies there are two different styles, both of which will be discussed below:
In informative study of products there are many situations where comparison is an adequate method. You could, for example, study comparable products which have been designed by different designers or made by different producers. Or you can study the same type of products as they are used in the same circumstances but in different countries.
An example of comparison can be found in the study Products as
Representations, by Susann Vihma. She examined metaphors of domestic
equipment. Among her study objects were twelve steam irons, five of which are
presented in the photo above. She found out that when studying each specimen in
separation it was not easy to grasp its symbolic message; it became easier when the
object was studied together with other similar objects or when two objects could be
compared to each other.
Comparison may be useful even when the researcher is not interested in differences but in a single case. If the interesting object belongs to the researcher's own cultural environment, it is not always easy to perceive its special characteristics. The case may appear too obvious and non-problematic. "A fish cannot see that it is living in water." One method to reveal the specific nature of a too well known object is to compare it to other cases or specimens from another context.
In exploratory study it often happens that you must gradually add new aspects of comparison, or redefine them when your knowledge of the object increases. It is also common that in the initial phases of the study you only reach descriptive answers to the question what the object is and what it is like, and from this basis you can then try to explain or answer the question why the object is as it is.
| Case 1 | Case 2 | |
| Potential reason | + | -- |
| Potential effect | + | -- |
Of course, a mere correlation between two variables does not yet definitively confirm a hypothetical explanation, because the correlation can be due to another possible explication.
Especially field work tends to entail, in spite of its usually good validity, often mediocre reliability of the findings because of disturbances that obstruct discovering those relationships that the researcher would want to study. If such is the case, you should consider complementing the comparison with other methods like interview (if people are mixed up in the activity to be studied) or an experiment with appropriate shielding to keep out any disturbing influences.
The difference between informative and normative styles of comparison is that in normative analysis one of the principal criteria is evaluative like "satisfaction", "usefulness" etc., and the aim of the study is to point out the best (in this respect) among the alternatives that are being studied. Moreover, the final aim perhaps is not only to find the best, but also to improve it or similar objects later on, and comparative analysis is expected to provide grounds for the planning of improvements in existing circumstances or products.
An example can be taken from Apuli-Suuronen (1999). She compared the written curricula of Finnish and Swedish high schools from the viewpoint of visual arts and found that political and cultural changes can explain many changes of curricula in the respective societies. However, today the development of curricula seems to lag behind the fast development of culture. She asks, "is it worth while to teach a student born into visual culture just to produce text from another text?" and tries to point out strategies for developing the Finnish, and perhaps also the Swedish, curriculum of visual arts so that it would help the modern student to meet the changing requirements and challenges of the future, particularly when creating, experiencing and understanding pictures. (Pp. 319-323.)
Because all evaluation is subjective it is important to consider and define exactly whose point of view is used in the evaluation; this aspect is discussed elsewhere under the titles of Human Subjectivity and Objectivity and Normative Research. Often the most interesting opinions come from people who have been using the product that is now going to be improved; sometimes it is the target group of future customers whose viewpoints are essential. If the normative suggestions that you are preparing shall be used by an organisation, for example in an enterprise of business, the choice of viewpoint depends also on the degree of autonomy which prevails on the various levels of the organisation.
In any case, it is the task of the researcher to define the population of people whose opinions and evaluations shall be collected. If their number is very great, you cannot contact all of them and you have to consider constructing a sample of this population. Once the evaluators have been selected, the assessments can be gathered with a survey.
Sometimes you can make use of already existing sources of evaluations, like the Customer Feedback System, if the company has one, or the public critique that some institutions, associations and journals generate and publish habitually.
| Car model: | A | B |
|---|---|---|
| Number of seats | 5 | 8 |
| Number of doors | 5 | 4 |
| Air bags | Yes | No |
| Fuel consumption | 5,8 | 6,5 |
| Special merits | ... | ... |
| Price | 8500 | 9900 |
In comparative study products are usually viewed as holistic entities, each of which possesses a given, fixed set of attributes.
Such a holistic comparison of products is meaningful and practical when you want to compare a number of existing products. However, it is not very efficient when you need to specify or invent such improvements to the present state of things that have not yet been achieved among the cases that can be studied. It has the same drawback than the iterative method of planning or design (see figure on the right): it cannot point out new alternatives, such combinations of properties that differ radically from the known ones.
Thus, if you want to include in your comparison not only already existing products but also "virtual" alternatives: new theoretical combinations of attributes, you have to use methods that can handle directly the attributes of products. Such methods are described under the titles Normative Study of Variables. Especially regarding Product Development methods, there are the methods of Presenting a Product Concept and Presenting the Draft and Prototype.
On the principles and methods of normative study there is also a separate page.
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January 2, 2004. Original location:
http://www2.uiah.fi/projects/metodi
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